• Aerospace Engineering and Technology
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• v.2 no.2
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• pp.18-24
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• 2003

Center of buoyancy moves along with pitch attitude variation, which causes Helium gas inclination. In this paper, movement of center of buoyancy and corresponding variation of longitudinal static stability were observed. The effect of separating wall, which is placed in the envelop to minimize movement of center of buoyancy was also investigated. Installation of separating wall was proved to be essential for current design, because movement of center of buoyancy aggravates longitudinal static stability. Investigation of longitudinal static stability for various speeds reveals a 50m airship is statically stable only in a low speed regime.

• Journal of the Korean Institute of Landscape Architecture
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• v.13 no.2
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• pp.1-12
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• 1985

인간은 역사적으로 의식주와 같은 기본적 생존과는 무관한 '아름다움'을 왜 그토록 열렬히 추구해 왔는가\ulcorner 본 논문은 이러한 문제의 해답을 찾고자 실험미학자인 벌라인 (Berlyne)의 이론을 중심으로 미적 반응에 관한 고찰을 하였으며 다음의 사항을 다루고 있다. 1) 미적 반응을 '자극-반응'의 동적 과정으로서 이해하고 이러한 종적 과정의 구조적 측면을 고찰하였다. 2) 미적 반응의 심리생물학적 작용을 고찰하였다. 3) 미적 반응을 초래하는 자극의 특성을 고찰하였다. 4) 미적 반응의 하나인 시각적 선호에 관한 기존의 연구를 검토하였으며, 시각자원연구에의 응용 가능성이 높음을 고찰하였다.

• Journal of Korean language education
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• v.28 no.4
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• pp.1-38
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• 2017

This longitudinal study analyzed syntactic development (Complexity, Accuracy, and Fluency; CAF) of six L2 Korean learners in a natural learning context. The learners recalled the stories of a short animated video through speaking and writing every 3 months, from month 0 to 15. The learners' responses were analyzed for a series of CAF measures and their cognitive, psychological, and social variables were investigated. The results showed that (i) L2 Korean learners' speaking and writing in various time periods showed significant differences in spoken and written accuracy, and complexity; (ii) the correlation between spoken and written complexity, spoken and written accuracy, as well as spoken and written fluency were significant, and (iii) the regression analysis showed that learners' cognitive, social, and psychological variables have significant effect on the L2 Korean syntactic development. The current study reports that L2 Korean learners engaged in self-learning in a natural learning environment without formal instruction made significant syntactic development.

• Journal of Chest Surgery
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• v.34 no.3
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• pp.264-269
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• 2001

흉부 둔상에 의한 기도와 식도의 동시적 파열상은 매우 드물게 발생되고 있다. 그러나 최그들어 고속 교통사고의 증가와 환자에 대한 응급체계의 발전으로 점차 치험 보고례가 증가되고 있다. 저자들은 흉부의 둔상에 의하여 기도와 식도에 종적으로 긴 파열상을 입은 환자 2례의 치험을 보고한다. 1례는 이전 병원에서 시행한 기관식도 재건술이 실패한 상태에서 전원되어와 2차적으로 식도절제 및 기관재건술을 실시하였으나 사망하였고. 다른 1례는 식도절제 및 기도재건술로 합병증이 없이 생존하였다.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.42 no.3 s.333
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• pp.1-8
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• 2005

In this paper, we analyzed the DC and RF characteristics of $0.1\;{\mu}m$ metamorphic high electron mobility transistor (MHEMT) using the ISE-TCAD simulation tool. we also analyzed the effects or the scaling on vertical and lateral dimensions such as a gate length, source-drain spacing, and channel thickness. We discussed the degradation of extrinsic transconductance $g_{m,max}$ in the MHEMTs adopting the gate length $(L_g)$ of $sub-0.1\;{\mu}m$. We suggested the model describing the effects on the vertical and lateral parameter scaling.

• Journal of the Korean Society of Safety
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• v.31 no.1
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• pp.139-147
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• 2016

Nuclear energy is considerably cheap and clean compared to other fossil fuels. Yet, there are rising safety concerns of nuclear power plants including the possibility of radiation releasing nuclear accidents. In light of the Fukushima nuclear crisis in 2011, Japan has been re-evaluating their existing energy policies and increasing the share of alternative energy. This paper first tracks the major historical changes of energy policy in Japan by time period. Next, energy security, reignited concerns and alternative energy are covered to examine Japan's energy security situation and its transition after the Fukushima disaster. Lastly, a short survey based on thematic analysis was conducted in South Korea and Japan to understand the public awareness of nuclear. This paper postulates that the case of Fukushima will contribute to establish and operate a safe-future nuclear program in South Korea, given that the country is not only geographically neighbouring Japan but also the world's fourth largest producer of nuclear energy.

• School Mathematics
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• v.19 no.2
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• pp.229-248
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• 2017

This study investigated the factors that should be considered when teaching proportional expression and proportional distribution through literature review. Based on these results, we analyzed and compared Korean and foreign mathematics textbooks on proportional expression and proportional distribution longitudinally and horizontally to search for desirable methods of organizing the unit of proportional expression and proportional distribution in mathematics textbooks. For longitudinal analysis, we took the mathematics textbooks according to the national curriculum since the 5th one. For horizontal analysis, we selected the mathematics textbooks of Japan, Singapore, and China. In each textbook, the contents and the order in relation to proportional expression and proportional distribution, the definitions of terminology, and the contexts and the visual representations for introducing related concepts are selected as the analysis framework. The results of analysis revealed many characteristics and the differences in ways of dealing contents about proportional expression and proportional distribution. Based on these results, we suggested some implications for writing the unit of proportional expression and proportional distribution in elementary mathematics textbooks.

• Journal of Korean Elementary Science Education
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• v.41 no.2
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• pp.173-185
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• 2022

The purpose of this study is to present a reflective review of the earth and universe units from the revised elementary curriculum of 2007-2015 and suggest changes in the 2022 revised curriculum. For this purpose, we conducted an FGI with earth science educators and elementary school teachers regarding the content elements and system, the achievement standards and inquiry activity composition, and the vertical and horizontal curriculum connectivity. Free response and weighted hierarchical analysis items were incorporated into the FGI to ensure logical consistency of the inductively derived improvement. This analysis revealed that the composition of units by grade group had been unevenly distributed among each of the "earth systems" until the 2015 revised curriculum was finalized. Furthermore, the basic concept was still insufficient. We suggest that achievement standards centered on the learning content and skills must state specific scientific core competencies, and inquiry activities should include rigorous critical thinking, student written responses, and student inquiry and analysis. In the hierarchical analysis items, FGI emphasized the inclusion of essential content elements rather than reduction of content elements, understanding-oriented concept learning rather than interest-centered phenomenon learning, basic concept division learning before integration between subjects, and expanding vertical-horizontal connectivity rather than repeating and advancing learning. There is a limit to the generalizing the suggestions proposed in this study to the common opinion of elementary earth science experts. However, since the main vision of the 2022 revised curriculum is to gather opinions through educational entities' participation in a variety of educational subjects, it is suggested that our results should be incorporated as one of the opinions proposed for the 2022 curriculum revision.

• The Journal of the Korea Contents Association
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• v.10 no.5
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• pp.370-378
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• 2010

The aims of this research are to grasp the supporting volition of the government as increasing multicultural family and discussing direction of the work and program for them. Therefore, this article inquired into the structure and the view through the supporting the law in 2008 and policy in 2009 of multicultural family and the contents of the work and program divided into the fields of essentiality and speciality for the multicultural family support center. As a result, this article implied three directions ; first, the practicality of contents based on the needs and requirement of multicultural family, second, the connection of multicultural family life cycle based on circumstances and resources, third, the mutual direction of effect based on promoting the character of a nation between multicultural family and others.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.40 no.3
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• pp.285-296
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• 1995

Anatomical studies of sink tissues are required for better understanding the biological plant growth system and energy metabolism. Kinematics of root growth zones of two genotypes of tall fescue (Festuca arundinacea Schreb.) receiving 50 or 200 ppm N were determined. Longitudinal anatomy and cell dynamics of root growth zones were studied and calculated. The root growth zone is organized similarly to the leaf growth zone which has cell division, elongation, and maturation zones, but the root growth zone is only about 3.0 mm long compared to 25 to 30 mm for the leaf growth zone. The root cap extends about 0.4 to 0.5 mm from the apical initial, while the cell elongation zone for both cortical and metaxylem cells extends about 3.3 mm from the apical initial for both genotypes and N levels. Root cap cells elongate from an initial length of about 5$\mu{m}$ long to a final length of about 40$\mu{m}$ before being sloughed. Initial lengths of cortical and metaxylem cells were about 8.5 $\mu{m}$ and 13.0 $\mu{m}$, respectively. Elongation of cortex and metaxylem cell showed sigmoidal curves with final lengths of about 120 $\mu{m}$ for cortex cells and 650 $\mu{m}$ for metaxylem cells. Initial size and final size for both types were not affected by N level, but cell fluxes and cell elongation rates of cortical and metaxylem cells were about double in low N. Cell production rates were about 5 to 6 times higher in cortical cells than in metaxylem cells. Differences in N caused a larger change in cell production rate, duration of cell elongation, and relative cell elongation rate than did the genotypes. These data indicate that N application affects root growth longitudinally by changing cell production rate and elongation rate.